Gods, if only it was that easy. Supposedly higher wages, while it may increase overall participation, also pushes some folks out of the market, or something along those lines. Either by out pricing their skillset or forcing the businesses to hire fewer, more efficient workers (because they're only a per worker cap from being willing to hire more people, rather than, y'know, see fewer more efficient workers as the base state of hiring heuristics or somethin').
Think it's something like an assumption we're already at or near peak employment so far as higher wages go (or the ones being hired are assumed by dint of their clear higher paying job superiority to have been able to obtain the position anyway), but have this weird low wage lot that isn't tapped, and will surely show up if you lower standards (and consequently wages) enough. Probably some of that fundamental attribution error thing going on, heh. Some kind of base assumption that not having work means you're unskilled to the points companies need to lower standards to be able to afford hiring you, something along those lines.
... and yeah, sure. Most observations, base understanding of economics, and so on, and so forth, signal pretty insistently that that shit ain't gon' work. Stuff gets labeled voodoo economics for a reason, heh.